A few days ago our dryer started complaining about a blocked airway, so I went up on the roof to check out the vent and sure enough the screen was completely clogged with lint.
It's a new vent that was installed along with a new roof in November, so I imagine I'll have to go up there and clean it out every 3-4 months.
Is this really part of regular home maintenance? Neither my wife nor I recall our parents ever doing this sort of thing.